Main Pros & Cons

Multiple Gravity forms plugin extending functionalities

Documentation & support are good

Hooks much better in gravity forms : there’s a php hook for almost every step of process

Conclusion

To me, it seems obvious that Gravity Forms is better, from several points of view. But, if you only need a plugin for displaying forms (that can be very complex), you can go with FSQM Pro without any problem. If you need to code php that communicate with those plugin, definitely Gravity Form is much better for that, with all the hooks prepared and extended documentation.
If this can save you a few hours of tests, as i did, i would be happy ! 🙂